Ultra-high pressure processing technology involves food technology, microbiology, physics, sensors, automation technology and other disciplines. Due to the high equipment cost and huge investment, the ultra-high pressure processing technology of food in China is still in the research stage, and there is no mature ultra-high pressure sterilization technology put into food industry production, but ultra-high pressure food conforms to the characteristics of simplicity and safety of new food in 2 1 century.
This paper briefly summarizes the research on microwave sterilization at home and abroad in recent years from the aspects of the sterilization effect of microwave on instruments, the influence of microwave sterilization on instrument parameters, sterilization equipment and sterilization mechanism. A large number of research reports show that microwave is an effective method to achieve safe, reliable and efficient sterilization, but the specific conditions of microwave sterilization for different instruments and different strains need experimental research.
According to the general workflow of food aseptic packaging, the packaging materials (or containers) and auxiliary equipment are sterilized-the packaged products are sterilized (that is, the products are sterilized) → the operating environment is sterilized (aseptic packaging) → the products are sterilized. That is to say, in order to realize the aseptic packaging of food, there must be four elements, namely, ensuring the aseptic packaging of food, packaging materials and containers, packaging machinery (tools) and operating environment, and finally requiring complete sealing and aseptic packaging. Therefore, food aseptic packaging should pay attention to the selection and sterilization of packaged food and packaging materials, as well as the sterilization of packaging equipment and environment during the whole operation.
Sterile packaging of food should be sterilized and cooled before packaging to ensure sterility; At present, there are many sterilization methods, such as superheated steam sterilization, saturated steam sterilization, dry hot air sterilization, humid hot air sterilization, ultraviolet sterilization, radiation sterilization, microwave sterilization, chemical sterilization and so on. In addition to being used alone, sometimes two or more sterilization methods are used at the same time to improve the sterilization effect. The specific choice of sterilization method should mainly depend on the nature of food, and the same sterilization method has great differences in the effects of different foods. If the diameter or edge of solid particles in food reaches 15mm, double-layer tubes and scraper heat exchangers can be used for heating and cooling. However, it takes a long time for liquid food containing larger solid particles to reach temperature balance, so the heating, heat preservation and cooling time must be greatly extended.